THE RELATION BETWEEN AGN GAMMA-RAY EMISSION AND PARSEC-SCALE RADIO JETS
We have compared the radio emission from a sample of parsec-scale active galactic nucleus (AGN) jets as measured by the VLBA at 15 GHz, with their associated {gamma}-ray properties that are reported in the Fermi Large Area Telescope (LAT) three month bright source list. We find in our radio-selected sample that the {gamma}-ray photon flux correlates well with the quasi-simultaneously measured compact radio flux density. The LAT-detected jets in our radio-selected complete sample generally have higher compact radio flux densities, and their parsec-scale cores are brighter (i.e., have higher brightness temperature) than the jets in the LAT nondetected objects. This suggests that the jets of bright {gamma}-ray AGN have preferentially higher Doppler-boosting factors. In addition, AGN jets tend to be found in a more active radio state within several months from LAT-detection of their strong {gamma}-ray emission. This result becomes more pronounced for confirmed {gamma}-ray flaring sources. We identify the parsec-scale radio core as a likely location for both the {gamma}-ray and radio flares, which appear within typical timescales of up to a few months of each other.
- OSTI ID:
- 21300758
- Journal Information:
- Astrophysical Journal (Online), Vol. 696, Issue 1; Other Information: DOI: 10.1088/0004-637X/696/1/L17; Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-4357
- Country of Publication:
- United States
- Language:
- English
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